Coal upgrade plant and method for manufacturing upgraded coal

ABSTRACT

A coal upgrade plant includes a dryer  1  that heats and dries coal before pyrolyzing the coal, and a scrubber  32  that treats a carrier gas discharged from the dryer  1  while catching a desorbed component desorbed from the coal when the coal is dried by the dryer  1 . The coal upgrade plant further includes a carrier gas circulation path  22  that guides the carrier gas treated by the scrubber  32  to the dryer  1 . A cyclone  28  is also provided on the upstream side of the scrubber  32 . Thus, mercury and/or mercury-based substances generated in the dryer  1  can be removed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a coal upgrade plant which pyrolyzescoal after drying the coal, and a method for manufacturing upgradedcoal.

2. Description of Related Art

Since low ranking coal such as sub-bituminous coal and lignite has alower carbonization degree and a higher water content than high rankingcoal, a calorific value per unit weight is lower. However, since thereare abundant deposits of low ranking coal, the low ranking coal isdesired to be effectively used. Thus, various coal upgrading techniqueshave been studied in which the calorific value of the low ranking coalis increased by performing pyrolysis after drying the low ranking coal,and upgraded coal is deactivated so as to prevent spontaneous combustionduring transportation or storage (e.g., Japanese Unexamined PatentApplication, Publication No. 2014-31462 (hereinafter referred to as JPA2014-31462)).

JPA 2014-31462 discloses that pulverized coal is fed into a pyrolysisfurnace, and mercury-based substances (HgS, HgCl₂ or the like) containedin a pyrolysis gas generated when coal is pyrolyzed are adsorbed to thepulverized coal and discharged outside of a system in order to preventan increase in the concentration of mercury in pyrolyzed coal with themercury-based substances being re-adsorbed to the pyrolyzed coal.

A temperature of pyrolyzing coal is 300° C. or more to 500° C. or less,and an evaporating temperature of mercury is about 400° C. Thus, it canbe said that it is technically appropriate to take into considerationthe generation of the mercury-based substances in a pyrolyzer asdescribed in JPA 2014-31462. Under such understanding, since a dryerused before the pyrolysis heats the coal to 150° C. or more to 200° C.or less to remove moisture in the coal, it has been considered that thegeneration of the mercury and/or the mercury-based substances is smallenough to be negligible.

However, as a result of earnest study, the present inventors confirmedthat there is a possibility that a non-negligible amount of mercuryand/or mercury-based substances is generated in the dryer used forremoving the moisture in the coal.

The present invention has been made in view of such circumstances, andan object thereof is to provide a coal upgrade plant and a method formanufacturing upgraded coal capable of removing mercury and/ormercury-based substances generated in a dryer.

BRIEF SUMMARY OF THE INVENTION

To achieve the above object, a coal upgrade plant and a method formanufacturing upgraded coal of the present invention employ thefollowing solutions.

That is, a coal upgrade plant according to one aspect of the presentinvention includes: a dryer that heats and dries coal before pyrolyzingthe coal; and a scrubber that treats a carrier gas discharged from thedryer while catching a desorbed component desorbed from the coal whenthe coal is dried by the dryer.

The above coal upgrade plant reduces a water content of the coal byheating and drying the coal by the dryer before pyrolyzing the coal.

The carrier gas is caused to flow through the dryer so as to dischargethe desorbed component desorbed from the coal when the coal is dried.Steam and pulverized coal are discharged as the desorbed componenttogether with the carrier gas. As a result of earnest study, the presentinventors found that a non-negligible amount of mercury and/ormercury-based substances is contained. The scrubber removes the mercuryand/or the mercury-based substances generated in the dryer.

The coal upgrade plant according to one aspect of the present inventionfurther includes a carrier gas circulation path that guides the carriergas treated by the scrubber to the dryer.

By guiding the carrier gas treated in the scrubber to the dryer by thecarrier gas circulation path, the carrier gas is circulated and reused.The consumption of the carrier gas can be thereby reduced.

Since the mercury and/or the mercury-based substances are concentratedin the dryer when the carrier gas is circulated without removing themercury and/or the mercury-based substances, it is particularlyeffective to remove the mercury and/or the mercury-based substances bythe scrubber.

The coal upgrade plant according to one aspect of the present inventionfurther includes a dust collector that is provided on an upstream sideof the scrubber.

The pulverized coal accompanying the carrier gas is separated by thedust collector provided on the upstream side of the scrubber. However,when the pulverized coal cannot be sufficiently separated by the dustcollector, the pulverized coal can be separated from the carrier gas bythe scrubber that is provided on the downstream side of the dustcollector.

A method for manufacturing upgraded coal according to one aspect of thepresent invention includes: a drying step of heating and drying coalbefore pyrolyzing the coal; and a carrier gas treating step of treating,by a scrubber, a carrier gas discharged in the drying step whilecatching a desorbed component desorbed from the coal when the coal isdried in the drying step.

The method for manufacturing upgraded coal according to one aspect ofthe present invention reduces a water content of the coal by heating anddrying the coal in the drying step before pyrolyzing the coal.

The carrier gas is caused to flow in the drying step so as to dischargethe desorbed component desorbed from the coal when the coal is dried.For instance, steam and pulverized coal are discharged as the desorbedcomponent together with the carrier gas. As a result of earnest study,the present inventors found that a non-negligible amount of mercuryand/or mercury-based substances is contained. In the carrier gastreating step, the scrubber removes the mercury and/or the mercury-basedsubstances generated in the drying step.

The mercury and/or the mercury-based substances generated in the dryercan be removed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating the entireconfiguration of a coal upgrade plant according to one embodiment of thepresent invention.

FIG. 2 is a configuration diagram schematically illustrating a dryingstep shown in FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In the following, one embodiment according to the present invention isdescribed by reference to the drawings.

FIG. 1 shows a coal upgrade plant according to one embodiment of thepresent invention. The coal upgrade plant includes a dryer 1 that heatsand dries coal, a pyrolyzer 3 that heats and pyrolyzes the dried coaldried in the dryer 1, a quencher 5 that cools the pyrolyzed coalpyrolyzed in the pyrolyzer 3, a finisher 7 that deactivates thepyrolyzed coal cooled in the quencher 5, and a briquetter 9 thatbriquettes the upgraded coal deactivated by the finisher 7 into apredetermined shape.

A coal hopper 12 that receives raw coal 10 is provided on the upstreamside of the dryer 1. The raw coal is low ranking coal such assub-bituminous coal and lignite, and has a water content of 25 wt % ormore to 60 wt % or less. The coal guided from the coal hopper 12 iscrushed to a particle size of, for example, about 20 mm or less in acrusher 14.

The coal crushed in the crusher 14 is guided to the dryer 1. The dryer 1is of indirect heating type using steam, and includes a cylindricalvessel 16 that rotates about a center axis, and a plurality of heatingtubes 18 that are inserted into the cylindrical vessel 16. The coalguided from the crusher 14 is fed into the cylindrical vessel 16. Thecoal fed into the cylindrical vessel 16 is guided from one end side (theleft side in FIG. 1) to the other end side while being agitatedaccording to the rotation of the cylindrical vessel 16. Steam having atemperature of 150° C. or more to 200° C. or less (more specifically,180° C.), which is produced in a steam system 20, is fed into each ofthe heating tubes 18, thereby indirectly heating the coal in contactwith the outer periphery of each of the heating tubes 18. The steam fedinto each of the heating tubes 18 is condensed after applyingcondensation heat by heating the coal, discharged from the dryer 1, andreturned to the steam system 20.

A carrier gas is fed into the cylindrical vessel 16 through a carriergas circulation path 22. As the carrier gas, an inert gas is used. Morespecifically, a nitrogen gas is used. When in shortage, the nitrogen gasis additionally fed from a nitrogen feed path 24 that is connected tothe carrier gas circulation path 22. The carrier gas is dischargedoutside of the cylindrical vessel 16 through a carrier gas dischargepath 26 that is connected to the cylindrical vessel 16 while catching adesorbed component (steam, pulverized coal, mercury, mercury-basedsubstances, etc.) desorbed from the coal when passing through thecylindrical vessel 16.

A cyclone (dust collector) 28, a carrier gas cooler 30, and a scrubber32 are provided in the carrier gas discharge path 26 sequentially fromthe upstream side of a carrier gas flow direction.

The cyclone 28 mainly removes the pulverized coal (for example, having aparticle size of 100 μm or less) that is a solid from the carrier gas byuse of a centrifugal force. The pulverized coal removed in the cyclone28 is guided to the upstream side of a bag filter 34 as indicated byreference character A. The pulverized coal separated in the cyclone 28may be also mixed into the dried coal dried in the dryer 1.

The carrier gas cooler 30 cools the carrier gas, from which thepulverized coal has been removed, thereby condensing steam guidedtogether with the carrier gas and removing the condensed steam as drainwater. The carrier gas cooler 30 is an indirect heat exchanger.Industrial water having a normal temperature is used as a coolingmedium. Recycled water separated in a waste water treatment equipment 40may be also used as the cooling medium. The drain water produced in thecarrier gas cooler 30 is guided to a liquid phase section in a lowerportion of the scrubber 32.

The scrubber 32 removes the mercury and/or the mercury-based substances(simply referred to as “mercury etc.” below) from the carrier gas, fromwhich the pulverized coal and the steam have been removed. Water is usedas an absorber in the scrubber 32. More specifically, the recycled waterseparated in the waste water treatment equipment 40 is used as theabsorber. The mercury etc. in the carrier gas is adsorbed by the watersprayed from above the scrubber 32, and guided to the liquid phasesection in the lower portion of the scrubber 32. In the scrubber 32, thepulverized coal that could not be removed in the cyclone 28 is alsoremoved.

An upstream end of the carrier gas circulation path 22 is connected toan upper portion of the scrubber 32. A blower 36 is provided at anintermediate position of the carrier gas circulation path 22. Thecarrier gas treated in the scrubber 32 is returned to the dryer 1 by theblower 36. Although not shown in the drawings, one portion of thecarrier gas treated in the scrubber 32 is guided to a combustor 42.

The waste water treatment equipment 40 is connected to the lower portionof the scrubber 32 through a waste water path 38. The waste watertreatment equipment 40 separates sludge 39, which is a solid contentsuch as the pulverized coal and the mercury etc., and the recycled waterby a sedimentation tank (not shown) after aggregating and enlarging themercury etc. by injecting a chelating agent into waste water. Therecycled water is reused in various portions of the plant.

The coal (dried coal) dried in the dryer 1 passes through a dried coalfeed path 44 to be guided to the pyrolyzer 3 by use of its weight. Thepyrolyzer 3 is an external-heat rotary kiln, and includes a rotatinginner cylinder 46, and an outer cylinder 48 that covers the outerperipheral side of the rotating inner cylinder 46. A nitrogen gas as acarrier gas is fed into the rotating inner cylinder 46.

A combustion gas produced in the combustor 42 is guided to a spacebetween the rotating inner cylinder 46 and the outer cylinder 48 througha combustion gas introduction path 50. Accordingly, the inside of therotating inner cylinder 46 is maintained at 350° C. or more to 450° C.or less (for example, 400° C.)

To the combustor 42, an air feed path 54 that guides combustion airforce-fed by a blower 52 into the combustor, a natural gas feed path 55that guides a natural gas as fuel into the combustor, and a pyrolysisgas collection path 56 that collects a pyrolysis gas generated in thepyrolyzer 3 together with the carrier gas, and guides the gas into thecombustor are connected. In the combustor 42, a fire 51 is formed by thenatural gas, the pyrolysis gas, and the air fed into the combustor.Since the pyrolysis gas contains a volatile content such as tar and hasa predetermined calorific value, the pyrolysis gas is used as fuel inthe combustor 42. The natural gas fed from the natural gas feed path 55is used for adjusting a calorific value of the fuel injected into thecombustor 42. A flow rate of the natural gas is adjusted such that thecombustion gas produced in the combustor 42 has a desired temperature.

A pyrolysis gas discharge path 58 that is used in emergency is connectedto an intermediate position of the pyrolysis gas collection path 56. Aflare stack 60 is installed on the downstream side of the pyrolysis gasdischarge path 58. A combustible component such as tar in the pyrolysisgas is incinerated by the flare stack 60, and a gas obtained after theincineration is released to the atmosphere.

A combustion gas discharge path 62 through which the combustion gasproduced in the combustor is discharged is connected to the combustor42. An upstream end of the combustion gas introduction path 50 thatguides the combustion gas to the pyrolyzer 3 is connected to anintermediate position of the combustion gas discharge path 62. A firstmedium-pressure boiler 64 is provided in the combustion gas dischargepath 62 on the downstream side of a connection position with thecombustion gas introduction path 50.

An after-heating gas discharge path 66 through which the combustion gasafter heating the rotating inner cylinder 46 is discharged is connectedto the outer cylinder 48 of the pyrolyzer 3. A second medium-pressureboiler 68 is provided in the after-heating gas discharge path 66. Theafter-heating gas discharge path 66 is connected to the combustion gasdischarge path 62 on the downstream side. A blower 70 that force-feedsthe combustion gas is provided in the combustion gas discharge path 62on the downstream side of a connection position with the after-heatinggas discharge path 66.

The downstream side of the combustion gas discharge path 62 is connectedto the bag filter 34. A flue gas, from which combustion ash or the likeis removed in the bag filter 34, is released to the atmosphere (ATM).

The steam system 20 includes the first medium-pressure boiler 64 and thesecond medium-pressure boiler 68. In the second medium-pressure boiler68, boiler feed water (BFW) fed thereto is heated by the combustion gasflowing through the after-heating gas discharge path 66, therebyproducing steam. Medium-pressure steam produced in the firstmedium-pressure boiler 64 and medium-pressure steam produced in thesecond medium-pressure boiler 68 are respectively stored in a steam drum(not shown), and fed to various portions of the plant such as theheating tubes 18 of the dryer 1.

The pyrolyzed coal pyrolyzed in the pyrolyzer 3 is guided to thequencher 5 through a pyrolyzed coal feed path 72 by use of gravity. Thequencher 5 includes a first cooler 74 that receives the pyrolyzed coalfrom the pyrolyzer 3, and a second cooler 76 that receives the pyrolyzedcoal cooled by the first cooler 74.

The first cooler 74 is a shell-and-tube heat exchanger, and includes afirst cylindrical vessel 78 that rotates about a center axis, a firstwater spray tube 79 that is inserted into the first cylindrical vessel78, and a plurality of first cooling tubes 80 that are inserted into thefirst cylindrical vessel 78. The first water spray tube 79 is installedin a stationary state with respect to the rotating first cylindricalvessel 78. The pyrolyzed coal having a temperature of 300° C. or more to500° C. or less (for example, about 400° C.), which is guided from thepyrolyzer 3, is fed into the first cylindrical vessel 78. The pyrolyzedcoal fed into the first cylindrical vessel 78 is guided from one endside (the left side in FIG. 1) to the other end side while beingagitated according to the rotation of the first cylindrical vessel 78.

Industrial water having a normal temperature is guided to the firstwater spray tube 79. The water is sprayed on the pyrolyzed coal andthereby brought into direct contact with the pyrolyzed coal to cool downthe pyrolyzed coal. The first water spray tube 79 is provided on theupstream side (the left side in FIG. 1) of the pyrolyzed coal movingwithin the first cylindrical vessel 78. The recycled water separated inthe waste water treatment equipment 40 may be used as the water fed tothe first water spray tube 79.

Boiler feed water having a temperature of 50° C. or more to 100° C. orless (for example, about 60° C.) is fed into each of the first coolingtubes 80, thereby indirectly cooling the pyrolyzed coal in contact withthe outer periphery of each of the first cooling tubes 80. Each of thefirst cooling tubes 80 is provided on the downstream side (the rightside in FIG. 1) of the pyrolyzed coal moving within the firstcylindrical vessel 78. Each of the first cooling tubes 80 cools thepyrolyzed coal cooled by the first water spray tube 79 to about 150° C.that is equal to or higher than a condensation temperature of water.

The second cooler 76 has substantially the same configuration as thefirst cooler 74. The second cooler 76 is a shell-and-tube heatexchanger, and includes a second cylindrical vessel 81 that rotatesabout a center axis, a second water spray tube 82 that is inserted intothe second cylindrical vessel 81, and a plurality of second coolingtubes 83 that are inserted into the second cylindrical vessel 81. Thesecond water spray tube 82 is installed in a stationary state withrespect to the rotating second cylindrical vessel 81. The pyrolyzed coalcooled to about 150° C. in the first cooler 74 is fed into the secondcylindrical vessel 81. The pyrolyzed coal fed into the secondcylindrical vessel 81 is guided from one end side (the left side inFIG. 1) to the other end side while being agitated according to therotation of the second cylindrical vessel 81.

Industrial water having a normal temperature is guided to the secondwater spray tube 82. The water is sprayed on the pyrolyzed coal toadjust the water content of the pyrolyzed coal to a desired value (forexample, 8 wt %). The second water spray tube 82 is provided oversubstantially the entire second cylindrical vessel 81 in an axialdirection. The recycled water separated in the waste water treatmentequipment 40 may be used as the water fed to the second water spray tube82.

Industrial water having a normal temperature is guided into each of thesecond cooling tubes 83, thereby indirectly cooling the pyrolyzed coalin contact with the outer periphery of each of the second cooling tubes83. Each of the second cooling tubes 83 cools the pyrolyzed coal toabout 50° C. The recycled water separated in the waste water treatmentequipment 40 may be used as the water fed to each of the second coolingtubes 83.

The pyrolyzed coal cooled in the quencher 5 is guided to the finisher 7through a cooled pyrolyzed coal feed path 84.

The finisher 7 includes a first deactivator 86 that receives thepyrolyzed coal cooled in the quencher 5, and a second deactivator 88that receives the pyrolyzed coal from the first deactivator 86.

An oxidation gas having an oxygen concentration of about 0.5 to 3.0% isguided into the first deactivator 86 from a first oxidation gas feedpath 90. Although not shown in the drawings, oxygen (more specifically,air) is fed to the first oxidation gas feed path 90 so as to adjust theoxygen concentration to a desired value.

The oxidation gas fed into the first deactivator 86 oxidizes an activespot (radical) generated by the pyrolysis to deactivate the pyrolyzedcoal within the first deactivator 86. The oxidation gas discharged fromthe first deactivator 86 is guided to a first blower 92 through a firstoxidation gas outlet tube 91 together with the pulverized coal. Theoxidation gas force-fed by the first blower 92 is guided to the firstoxidation gas feed path 90 again, and recirculated. The oxidation gasguided not to the first oxidation gas feed path 90, but to an oxidationgas discharge tube 93 is guided to a cyclone 94. The solid content suchas the pulverized coal is separated from the oxidation gas guided to thecyclone 94 in the cyclone 94, and the resultant gas is guided to the bagfilter 34 and released to the atmosphere (ATM). The solid content suchas the pulverized coal separated in the cyclone 94 is fed to a kneader100.

The pyrolyzed coal is injected from an upper portion of the firstdeactivator 86, and deactivated in contact with the oxidation gas whiledescending. The pyrolyzed coal retained in a lower portion of the firstdeactivator 86 is taken out from the lower portion, and guided to anupper portion of the second deactivator 88.

An oxidation gas having an oxygen concentration of about 8.0 to 12.0% isguided into the second deactivator 88 from a second oxidation gas feedpath 95. Although not shown in the drawings, oxygen (more specifically,air) is fed to the second oxidation gas feed path 95 so as to adjust theoxygen concentration to a desired value.

The oxidation gas fed into the second deactivator 88 further deactivatesthe pyrolyzed coal deactivated in the first deactivator 86. Theoxidation gas discharged from the second deactivator 88 is guided to asecond blower 97 through a second oxidation gas outlet tube 96 togetherwith the pulverized coal. The oxidation gas force-fed by the secondblower 97 is guided to the second oxidation gas feed path 95 again, andrecirculated. The oxidation gas guided not to the second oxidation gasfeed path 95, but to the oxidation gas discharge tube 93 is guided tothe cyclone 94. The solid content such as the pulverized coal isseparated from the oxidation gas, and the resultant gas is guided to thebag filter 34 and released to the atmosphere.

The upgraded coal deactivated in the finisher 7 has a particle size ofabout 1 mm. The upgraded coal passes through an upgraded coal feed path98 to be guided to the kneader 100. The pulverized coal separated in thecyclone 94 is guided to the upgraded coal feed path 98 through apulverized coal collection path 99.

A binder guided from a binder feed section 102, the upgraded coalincluding the pulverized coal, and water are fed to and kneaded in thekneader 100. Examples of the binder include polyethylene oxide andstarch. The upgraded coal kneaded in the kneader 100 is guided to thebriquetter 9.

The briquetter 9 includes a female mold where a plurality of recessedportions having a shape corresponding to the product shape of theupgraded coal are formed, and a male mold that compresses the upgradedcoal fed into the recessed portions by pressing. The upgraded coalbriquetted in the briquetter 9 becomes upgraded coal 104 as a product.The upgraded coal 104 has a size of about several cm, and has a watercontent of 6 wt % or more to 9 wt % or less. Note that the water contentof the upgraded coal 104 is based on a dry weight when the water contentis in equilibrium with a storage environment, and the water contentlargely depends on relative humidity of the storage environment, butdoes not much depend on the temperature. For example, PRB (powder riverbasin) coal has a water content of about 8 wt % when the relativehumidity is 90%.

Next, the features of the present invention are described by using FIG.2.

FIG. 2 schematically shows the configuration around the above dryer 1.That is, the configuration in which the carrier gas discharged from thedryer 1 passes through the cyclone 28, the carrier gas cooler 30, andthe scrubber 32, and is recirculated to the dryer 1 through the carriergas circulation path 22 is shown.

In the cyclone 28, the pulverized coal contained in the carrier gasdischarged from the dryer 1 is removed. The pulverized coal removed inthe cyclone 28 is guided to the bag filter (see reference numeral 34 inFIG. 1).

In the carrier gas cooler 30, the steam contained in the carrier gas iscondensed and removed as the drain water. The drain water is guided tothe liquid phase section of the scrubber 32.

In the scrubber 32, the mercury etc. contained in the carrier gas andthe pulverized coal that could not be removed in the cyclone 28 areremoved. A large portion of the carrier gas treated in the scrubber 32is guided to the dryer 1 through the carrier gas circulation path 22.Also, one portion of the carrier gas is guided to the combustor (seereference numeral 42 in FIG. 1). The absorber (waste water) adsorbingthe pulverized coal and the mercury etc. in the scrubber 32 is guided tothe waste water treatment equipment 40.

In the waste water treatment equipment 40, the solid content such as thepulverized coal and the mercury etc., and the recycled water areseparated by the sedimentation tank (not shown) after aggregating andenlarging the mercury etc. by injecting the chelating agent into thewaste water.

As described above, the following effects are produced by the presentembodiment.

The present inventors found that a non-negligible amount of mercury etc.is generated even in the dryer 1 that operates in a temperature range(150° C. or more to 200° C. or less) falling below about 400° C. that isthe evaporating temperature of the mercury. Thus, the scrubber 32 thattreats the carrier gas discharged from the dryer 1 while catching thedesorbed component desorbed from the coal when the coal is dried by thedryer 1 is provided. Accordingly, the mercury etc. generated in the coaldrying step can be removed. The amounts of the mercury released to theatmosphere, and the mercury contained in the upgraded coal can be alsoreduced.

By guiding the carrier gas treated in the scrubber 32 to the dryer 1 bythe carrier gas circulation path 22, the carrier gas is circulated andreused. The consumption of the carrier gas can be thereby reduced. Forexample, when coal having a water content of 27.5 wt % or less is driedby using N₂ as the carrier gas, it is possible to suppress theconsumption of N₂ to 14% or less.

Since the mercury etc. is concentrated in the dryer 1 when the carriergas is circulated without removing the mercury etc., it is particularlyeffective to remove the mercury etc. by the scrubber 32.

After the pulverized coal accompanying the carrier gas is separated bythe cyclone 28 that is provided on the upstream side of the scrubber 32,the pulverized coal is further separated by the scrubber 32.Accordingly, it is possible to prevent the pulverized coal from beingreleased to the atmosphere as much as possible.

-   1 Dryer-   3 Pyrolyzer-   5 Quencher-   7 Finisher-   9 Briquetter-   10 Raw coal-   12 Coal hopper-   14 Crusher-   16 Cylindrical vessel-   18 Heating tube-   20 Steam system-   22 Carrier gas circulation path-   28 Cyclone-   30 Carrier gas cooler-   32 Scrubber-   34 Bag filter-   40 Waste water treatment equipment-   42 Combustor-   46 Rotating inner cylinder-   48 Outer cylinder-   50 Combustion gas introduction path-   74 First cooler-   76 Second cooler-   78 First cylindrical vessel-   79 First water spray tube-   80 First cooling tube-   81 Second cylindrical vessel-   82 Second water spray tube-   86 Second cooling tube-   86 First deactivator-   88 Second deactivator-   100 Kneader-   104 Upgraded coal

What is claimed is:
 1. A coal upgrade plant comprising: a dryer thatheats and dries coal before pyrolyzing the coal; and a scrubber thattreats a carrier gas discharged from the dryer while catching a desorbedcomponent desorbed from the coal when the coal is dried by the dryer. 2.The coal upgrade plant according to claim 1, further comprising acarrier gas circulation path that guides the carrier gas treated by thescrubber to the dryer.
 3. The coal upgrade plant according to claim 1,further comprising a dust collector that is provided on an upstream sideof the scrubber.
 4. A method for manufacturing upgraded coal comprising:a drying step of heating and drying coal before pyrolyzing the coal; anda carrier gas treating step of treating, by a scrubber, a carrier gasdischarged in the drying step while catching a desorbed componentdesorbed from the coal when the coal is dried in the drying step.